Proximity of Optic Radiations to Nearby Structures. A, Lateral view, showing the site of the different measurements. The A–C line represents the distance between the head of the hippocampus (A) and the anterior edge of the optic radiation (C) and averaged 5 mm (range, 3–6 mm). The C–D line represents the distance between anterior edge of the optic radiation (C) and the temporal pole (D) and averaged 25 mm (range, 22–30 mm). The B–C line represents the distance from the anterior tip of the temporal horn (B) to the anterior edge of the optic radiation (C) and averaged 2 mm (range, 1–3 mm). b, Inferior view. The A–B line represents the distance between the anterior edge of the lateral geniculate body (B) and the anterior point of the optic radiation (A) and averaged 22 mm (range, 20–25 mm). The arrow is on the anterior edge of the left optic radiation. (Images courtesy of E de Oliveira)